FIG. 1 of the appended drawings shows a side view of a rotating electrical power and fluid supply column currently installed in certain blow molding or stretch blow molding container manufacturing machines built by the applicant and representing the closest prior art.
The main parts of such a machine are simply sketched in a highly schematic form in FIG. 1.
The rotating machine shown in FIG. 1, of the carousel type, comprises a fixed bed 1 carrying a rotating frame 2 which revolves around an axis 3 of rotation.
The rotational drive means are not shown in FIG. 1.
The rotating frame 2 supports a number of workstations 4 set out at regular intervals around its periphery.
In the example considered, which is more specifically a stretch blow molding machine for producing containers such as bottles in a thermoplastic material such as PET, each workstation 4 comprises among other things:                a mold 5;        means 6 for controlling the preblowing fluid and the blowing fluid, and        a rod 7 for mechanically stretching the container as it is blown.        
The preblowing fluid is at a medium pressure of approximately 13×105 pascals.
The blowing fluid is at a relatively high pressure, typically 40×105 pascals.
The rod 7 for mechanically stretching the container as it is blown is moved axially by actuating means 8 of e.g. cylinder type.
These rod 7 actuating means 8 are supplied at a relatively low pressure, typically 7×105 pascals.
The machine also comprises a rotating electrical power and fluid supply column 9 that extends coaxially with the axis 3 of rotation of the rotating frame 2.
This rotating column 9 supplies the electrical power and delivers the various necessary fluids for the operation of the workstations 4, from fixed respective sources.
For this purpose, the rotating column 9 comprises an electrical commutator 10 at the head of the rotating column 9.
This electrical commutator 10 is supplied by a fixed electrical cable 11.
The rotating electrical commutator 10 possesses fixed or rotating tracks on which rotating or fixed pins, respectively, press elastically, the whole being protected under a casing 12.
This fixed casing 12 is kept stationary by an anti-torque structure 13 indicated schematically in the form of a bracket mounted on the fixed bed 1.
The rotating fluid connector 14 is positioned axially underneath the rotating electrical commutator 10. Only the casing 15 of this rotating fluid connector 14 is visible in FIG. 1.
This fixed casing 15 is kept in position by the anti-torque structure 13.
The rotating fluid connector 14 is connected by a conduit 16 to a source of pneumatic fluid at relatively high-pressure, typically air at 40×105 pascals.
The rotating fluid connector 14 is connected by a conduit 17 to a source of pneumatic fluid at relatively low pressure, typically air at an industrial pressure of 7×105 pascals.
The conduits 16, 17 are fixed and supported for example by the anti-torque structure 13.
The base 18 of the rotating supply column 9, through which it rests on the fixed bed 1, is also itself fixed. Another alternative structure may be envisioned, mainly that the fixed base 18 may be connected not to the fixed bed 1 but to the anti-torque structure 13.
The rotating part of the rotating column 9 can also be referred to as the rotor 19.
The workstation supplies are provided as follows.
The output electrical cables 20 of the rotating electrical commutator 10 are connected to the rotor 19 of the rotating column 9.
So as not to become tangled with the anti-torque structure 13, these cables 20 are passed through the rotating fluid connector 14 via a functional connection to the rotor 19 and, at the end of the rotating fluid connector 14, are connected to an electrical power supply cabinet 21 mounted on the rotating frame 2.
This cabinet 21 contains the electrical supplies for the electrical components of the workstations 4, notably the solenoid valves.
The pneumatic fluid is fed out of the rotating connector 14 to a rotating fluid directional control valve 22.
This rotating fluid directional control valve 22 is situated underneath the rotating fluid connector 14 and comprises:                a first level 23 of connectors distributed around the perimeter for distributing low-pressure pneumatic fluid;        a second level 25 of connectors distributed around the perimeter for distributing high-pressure pneumatic blowing fluid;        a third level 27 of connectors distributed around the perimeter for distributing medium-pressure pneumatic preblowing fluid.        
The first level 23 of connectors is connected at 24 to the actuating means 8 of the stretch rod 7.
The second level 25 of connectors is connected at 26 to the means 6 which control the aforementioned preblowing/blowing fluid.
The third level 27 of connectors is connected at 28 to the means 6 which control the aforementioned preblowing/blowing fluid.
The medium-pressure fluid, typically at 13×105 pascals is obtained by tapping off high-pressure fluid at 29 from the corresponding level of the rotating fluid directional control valve 22, the pressure of this high-pressure fluid being reduced in a pressure reducer 30 outside of the column 9 to lower it to the required pressure.
This reduced-pressure fluid is stored in a buffer tank 31, which may be integrated into a structure of the rotor 19 as shown in FIG. 1.
Below the buffer tank 31, the rotor 19 comprises a liquid directional control valve 32 for distributing at 33 and 34, to each workstation, the necessary water and/or oil, primarily for regulating the temperature of the molds 5.
In general terms, the rotating column 9 shown in FIG. 1 comprises, working down from the top:                a rotating electrical commutator 10;        a rotating fluid connector 14;        a rotating fluid directional control valve 22;        a medium-pressure pneumatic fluid buffer tank 31;        a rotating directional control valve 32 for the water and oil; and        a fixed base 18.        
A rotating electrical power and fluid supply column 9 set out as described above is currently fitted to many machines built by the applicant and is perfectly satisfactory from the functional point of view.
However, there are a number of disadvantages inherent in the structure of this known column.
In the first place, because it has so many components placed on top of each other, namely a rotating electrical commutator 10, a rotating fluid connector 14, a rotating fluid directional control valve 22, a medium-pressure pneumatic fluid buffer tank 31, a rotating directional control valve 32 for the water and oil, and a fixed base 18, this column 9 is very tall.
To reduce the size and volume occupied by a carousel-type rotating machine, it would therefore be highly desirable to produce a rotating column with a reduced height.
In the second place, it is found in practice that the rotating electrical commutator 10, which is right at the top of the column, requires attention relatively rarely, whereas relatively regular attention is required to the rotating fluid connector 14 or to the rotating fluid directional control valve 22, both of which are located below the electrical commutator 10.
In particular, the sealing rings between the fixed and rotating parts of the rotating fluid connector 14 or those of the rotating fluid directional control valve 22 regular need replacing because of their relatively short service life, the result of the severe mechanical stresses to which they are exposed.
To replace worn sealing rings in the rotating fluid connector 14 or in the rotating fluid directional control valve 22, it is first necessary to remove the electrical commutator 10 before accessing the rotating fluid connector 14. This operation of removing the electrical commutator 10 is time consuming and can result in damage to the electrical commutator 10—even though the commutator 10 is not in need of maintenance. Furthermore, access to the fluid members is limited.
It would therefore be particularly helpful to the industry to produce a rotating column from which the electrical commutator 10 did not have to be removed when maintenance was required on the rotating fluid connector 14 or on the rotating fluid directional control valve 22.